This parts is modeled after the vortex generator found on the Mitsubishi Evo MR. The idea is that the little triangle-shaped bumps will generate vortexes (or more properly, "vortices,") that allow the rear wing to work better, increasing rear downforce. Plus...they look cool.
Fiberglass and genuine carbon fiber construction. Attaches using included high-strength 3M adhesive. Fits all 2002-07 Impreza/WRX/STI.
Fitment note: This is a curved fiberglass/carbon part that fits on a rigid curved portion of the Subaru roof. Fiberglass varies somewhat in the mold process, so this item may take a little tweaking to fit.